- Ah, broadcast legal, a subject that hauntseditors, colorists, engineers and, of course,audio finishers as well.Before we look into ways to identifyand fix some common audio legality issues,I wanted to spend a couple minutesto discuss what I mean by broadcast legal for audio.First and foremost, the single largest legality issuefor audio has to do with levels.Now, that sounds (laughs) like a simple thing,but it's really not.Let me explain.

First, there's what you probably thinkof the normal measurement of level,what you see on a set of digital audio meters.Using the dBFS, or decibels full scale measurement,average and peak levels are often specifiedby a distributor or broadcaster.For example, a broadcaster might requirethat output levels not go over minus 10 dBFSor sometimes they might say decibels true peak,and I'll explain that next.Some outlets permit higher levels,like minus six or even minus three dBFS.

dBFS levels are also important for non-broadcast delivery.You might mix a project hotter for Vimeoor YouTube, since people will be viewingthat project on laptops, tablets and so on.So it's always a good idea to checkon your digital peak requirementsbefore you output your project.Next up, there is a measurement called true peak.Using the dBTP,or decibels true peak scale,true peak attempts to solve the correlationbetween digital peak and loudness,which we'll discuss shortly, as well as what happensto the audio signal when it's playedout of analog devices, like speakers on a viewer's TV.

Additionally, true peak attempts to measurefast transients that happen in a digitalto analog conversion that traditional limiting toolscan't even catch.True peak, along with loudness, has becomea very important measurement for most broadcasters.Now, there's still a little confusionon true peak legal levels, so yes, it's best (laughs)to check with your broadcaster or distributor.Here's the thing, though.To measure true peak, you need a true peak meter.

In Premiere, in Audition, well, we don't havea dedicated meter, and there's no true peak limiter, either.But we do have a warning on true peak,clipping, via the TC Electronics loudness meter,which I'll show you later in this chapter.And don't worry, that's bundledwith Premiere Pro and Audition.So speaking of loudness, as an editoror someone who's involved in broadcast,you've probably heard or will be hearinga lot about loudness.

Here in the U.S., there's even legislationabout loudness called the CALM Act.Put simply, loudness is perceptual volume.Loudness is important because sometimeswhile two audio clips will have the same digital level,one clip might sound louder than the other.That's loudness.While you'll sometimes see two different scales used,LUFS and LKFS,and these differ slightly in the math,they're essentially the same thing,with LKFS being the more popular measurement scale.

Most broadcasters will mandate loudness levelsof minus 24 LKFS,plus or minus two LKFS.Loudness is measured in two ways,momentary and average.Most broadcasters care most about the long-termor average loudness.Now, that's not to say that momentary loudnessdoesn't matter.It's a good way to check a particular sectionor part of a project.However, to get accurate, average measurementsthat a broadcaster will approve,you'll need to play down the entire projectand also reset the loudness radar in Premiere Proon each view to get accurate results.

In this chapter, we'll explore how to measure loudnesswith Premiere Pro's Loudness Radar plugin.Also, we'll take a look at how to QC audiobefore you output for broadcast,checking loudness levels and true peak,and I'll show you a way to do thatwith Adobe Audition a little bit later.Okay, if all this level stuff wasn't enough (laughs)there are other issues concerning broadcast legalitywhen it comes to audio.Track layout is very important.You need to check with your broadcasteror distributor, but giving them the correct tracksor stems is really important.

Do you need just a stereo mix?Do you need splits of different types,like dialogue only, music and effects, and so on?The thing to understand is that there's no standardwith these types of deliverables,so it's vital you make sure you knowwhat you need to deliver.Related to that is, do you need to deliverthese splits or stems with the videoor as separate files?And yes, I'm starting to soundlike a broken record, always check.Finally, with track deliverables,if you're delivering surround sound,you'll need to know the surround channel order.

Most of the time it'll be left, right, center,LFE, that's the subwoofer channel,then left surround and right surround.But before you make a mistake, yes,that's right, go ahead and check.Now that we've discussed the basics,up next we'll dive into measuring digitaland true peak, and how to use loudness measuring.And I'll give you some suggestionson how to fix issues, should you encounter them.

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Released

2/27/2015

Finishing is something every video project can benefit from. In this installment of Premiere Pro Guru, Robbie Carman guides editors through practical techniques for finishing the audio side of a video project, using Premiere Pro and Adobe Audition. He covers using track-level vs. clip-level controls, mastering the audio mixers, using submixes and automation modes, working with audio effects, reducing noise and restoring sound with Adobe Audition, and outputting audio from Premiere Pro. This course includes everything you need to know about mixing and sweetening audio yourself and handing off tracks to others to finesse.